Multicenter Surveillance of Capsular Serotypes, Virulence Genes, and Antimicrobial Susceptibilities of Causing Bacteremia in Taiwan, 2017-2019

We conducted a longitudinal epidemiological surveillance of hypervirulent (hvKP) in Taiwan. Bacteremic KP isolates collected from 16 hospitals in Taiwan between 2017 and 2019 were collected, and the virulent serotypes (K1, K2, K20, K54, and K57), antimicrobial susceptibilities, and virulence genes of these isolates were investigated. During the 3-year period, 1,310 bacteremic KP isolates were collected, of which 27.5% belonged to virulent serotypes, including K1 ( = 162), K2 ( = 74), K57 ( = 56), K54 ( = 41), and K20 ( = 27). K1 was the most prevalent capsular serotype, with an annual prevalence of 11-15%, and was equally distributed across the four geographic areas. The prevalence of K2 declined significantly in 2019. According to -K typing results, 87% of K1 isolates were classified as -1. Among K2 isolates, 72 (55.4%) and -2 (41.9%) were the most common, whereas -206 was the most prevalent (48.2%) among K57 isolates, followed by -77 (25.0%). -115 accounted for 85.4% of the K54 isolates, whereas -95 accounted for 92.6% of K20 isolates. was present in 99.4% of K1, 98.6% of K2, 89.3% of K57, 78.0% of K54, and 84.0% of K20 isolates. was present in 100% of K1 and 98.6% of K2 isolates but was only present in 64.3% of K57, 58.5% of K54, and 74.1% of K20 isolates. K1 remains the dominant hvKP serotype and is associated with most virulence genes in Taiwan. Further studies are required to elucidate the significance of other virulent serotypes.